Here’s another little tip about Supercharging performance that I think I learned here from @FlasherZ. In the settings of the car, you can change the units on the display to read either in distance or energy. If it is set for distance, the charging screen will show miles added per hour. If you change it to energy, it will show the power level in kilowatts. We talk about the Superchargers giving 120kW power level when all is ideal and how it slows down as the battery gets full. I think it was @FlasherZ who pointed out a nice ballpark is that the state of charge plus the number of kilowatts is usually around 120. So when your battery is 50% full, it will probably be around 70kW power. That’s a good way to see if the power from the Supercharger is appropriate or not.
Oh, one other thing is about the cold. I’m picking up on the clues on this. You said the temperature was 40 degrees, but that was probably referring to the daytime while you were driving, right? It probably got down to about 30 overnight, right? @mikeash referenced this part. If the battery is what we call “cold soaked”, where it has been outside in the cold for several hours, charging will be very slow at first. I’ve actually read on here a couple of stories where people gave up and left or panicked because they plugged into a Supercharger, and it didn’t do anything for 5 or 10 minutes. That was because their battery was at about 5 degrees Fahrenheit, and the system was warming the battery up before enabling any charging. Charging while the cells are really really cold is terrible and damaging to lithium ion battery cells. But you don’t have to worry about that, other than knowing it will take longer, because the Tesla battery management system makes sure to not damage your battery pack by using energy to warm it up first, before beginning charging. If you think of the physics of it, warming up a 1,000+ pound block of metal takes a while in 5 degree temperatures, so that will take some extra time.
So yeah, if it’s pretty cold, you might want to maybe fill most of it that evening while it’s still warm from driving and then maybe warm up/top off in the morning, after it has sat in the cold.
Oh, one other thing is about the cold. I’m picking up on the clues on this. You said the temperature was 40 degrees, but that was probably referring to the daytime while you were driving, right? It probably got down to about 30 overnight, right? @mikeash referenced this part. If the battery is what we call “cold soaked”, where it has been outside in the cold for several hours, charging will be very slow at first. I’ve actually read on here a couple of stories where people gave up and left or panicked because they plugged into a Supercharger, and it didn’t do anything for 5 or 10 minutes. That was because their battery was at about 5 degrees Fahrenheit, and the system was warming the battery up before enabling any charging. Charging while the cells are really really cold is terrible and damaging to lithium ion battery cells. But you don’t have to worry about that, other than knowing it will take longer, because the Tesla battery management system makes sure to not damage your battery pack by using energy to warm it up first, before beginning charging. If you think of the physics of it, warming up a 1,000+ pound block of metal takes a while in 5 degree temperatures, so that will take some extra time.
So yeah, if it’s pretty cold, you might want to maybe fill most of it that evening while it’s still warm from driving and then maybe warm up/top off in the morning, after it has sat in the cold.
